Of the many variants of earth protection devices, the optimal one for distribution networks is the zero-sequence power direction relay with electronic contactless circuit.

The study of transients of a certain level or phase of voltage at moments of short-circuit at multiple repetition is complicated by a number of difficulties: 1) short-circuit must occur each time at a given phase of voltage network; 2) the time of the closed state of the circuit (network) must exceed the duration of the transient with the subsequent automatic recovery of network parameters; observation or photographing the beginning of the leading edge of the transient process becomes impossible, since the entire process is conducted mainly with the help of cathode oscilloscopes.

Power System Modeling. Correct and reliable construction of power supply system and distribution of electric energy, research of modes of these systems as a whole and individual elements in particular, simplification of calculations and selection of optimal parameters can be achieved by physical modeling ...

Currently used schemes of protection against single-phase earth faults are unreliable or relatively slow-acting devices. The fact is that the main safety criteria in the creation of such protections have usually considered either random values or values insufficiently justified from the point of view of electrical safety ...

Single-phase ground faults in quarry distribution networks can occur as a result of: 1) human contact directly with live or metal structural parts suddenly energized due to insulation breakdown; 2) mechanical or any other damage to overhead or cable power lines ...